Phosphatidylinositol 3-kinase phosphorylates the inositol ring of phosphatidylinositol at the 3-prime position. The enzyme comprises a 110 kD catalytic subunit and a regulatory subunit of either 85, 55, or 50 kD. This gene encodes the 85 kD regulatory subunit. Phosphatidylinositol 3-kinase plays an important role in the metabolic actions of insulin, and a mutation in this gene has been associated with insulin resistance. Alternative splicing of this gene results in three transcript variants encoding different isoforms. [provided by RefSeq

Phosphoinositide 3-kinases (PI3Ks) phosphorylate the 3-prime OH position of the inositol ring of inositol lipids. They have been implicated as participants in signaling pathways regulating cell growth by virtue of their activation in response to various mitogenic stimuli. PI3Ks are composed of a 110-kD catalytic subunit, such as PIK3CB, and an 85-kD adaptor subunit (Hu et al., 1993 [PubMed 8246984]).[supplied by OMIM